There are a few ways you can edit the map, more specifically change the name of the road. First one is editing the road yourself - as a new user you can only edit roads that you have driven, so you will have to drive the area. See this wiki article for more infor.

Second option is to report an error directly from the map. You can do so from waze on your phone (you'll notice a little map edit menu on the main map, or also from the live map. Click on any street on the map and you will notice the option to report an error. Write the description in the box, and you will be updated once it is resolved.

As you make more changes to the map and become familiar with the map editor functions, you can become an area manager, to have full permissions on road names etc. over a pre-defined area.